Thermo-forming packaging machines are known from the applicant's EP 0 126 878 A1 and EP 1 816 075 A1 in which a film web is gripped with two clamping chains that are arranged on both sides of the film web and intermittently transported by the thermo-forming packaging machine. The width of the machine is determined by the width of the film web to be transported, or vice versa. The drawback of thermo-forming packaging machines having clamping chains arranged on two sides is that only a single film web width can be used corresponding to the distance of the clamping chains from each other, as conversion of the machine to a different film web width would entail an enormous effort and is technically very difficult to realize.